Question About Amazon/Kindle

Okay, this is for authors and readers, both. Anyone who uses a Kindle or Kindle app. Why is it whenever I edit one of my own Kindle books, I can’t get the new version on any of my devices? I delete the OLD version from the device, and I delete it (supposedly) permanently from the Cloud. Then I BUY a brand new version, download it, and it is the same version I had to start with. Every single time. After two years, I still can’t get the edited version of Wake-Robin Ridge on my Kindle.

What am I doing wrong? (Forget that part about checking the box to allow updated versions of books to automatically be sent to my Kindle. It has never worked on ANYONE’s book that I’m aware of.)  After uploading Finding Hunter a couple days ago, I discovered some wonky formatting going on that had NOT shown up on the Previewer. I fixed it, uploaded it, but have no way to tell how it looks on my own Kindle Voyage, because they merely sent me back my original purchase. ?????

Anyone else have this problem? Any help would be greatly appreciated.